Schottky diodes have several useful features and characteristics. When incorporated into integrated circuit (IC) technologies the Schottky diode enhances the range of diodes available. Typically, a Schottky diode consists of a metal layer connected to a doped semiconductor layer. The Schottky barrier is formed at the juncture of the metal and the semiconductor. Due to radius of curvature effects at the edges of the Schottky barrier, a field quickly builds up when a reverse bias is applied. This leads to a low breakdown voltage and poor leakage characteristics.
Breakdown voltage has traditionally been improved by placing a diffused p-type guard ring around the Schottky barrier, with the p guard ring short-circuited to the anode (metal plate) of the Schottky. This relieves the field, giving rise to a higher reverse voltage breakdown.